From owner-svn-src-all@FreeBSD.ORG Sun Nov 22 18:23:31 2009 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4AB12106566C; Sun, 22 Nov 2009 18:23:31 +0000 (UTC) (envelope-from jilles@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 39A2F8FC0C; Sun, 22 Nov 2009 18:23:31 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id nAMINV9O025965; Sun, 22 Nov 2009 18:23:31 GMT (envelope-from jilles@svn.freebsd.org) Received: (from jilles@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id nAMINVL5025958; Sun, 22 Nov 2009 18:23:31 GMT (envelope-from jilles@svn.freebsd.org) Message-Id: <200911221823.nAMINVL5025958@svn.freebsd.org> From: Jilles Tjoelker Date: Sun, 22 Nov 2009 18:23:31 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r199660 - head/bin/sh X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 Nov 2009 18:23:31 -0000 Author: jilles Date: Sun Nov 22 18:23:30 2009 New Revision: 199660 URL: http://svn.freebsd.org/changeset/base/199660 Log: Fix various things about SIGINT handling: * exception handlers are now run with interrupts disabled, which avoids many race conditions * fix some cases where SIGINT only aborts one command and continues the script, in particular if a SIGINT causes an EINTR error which trumped the interrupt. Example: sh -c 'echo < /some/fifo; echo This should not be printed' The fifo should not have writers. When pressing ctrl+c to abort the open, the shell used to continue with the next command. Example: sh -c '/bin/echo < /some/fifo; echo This should not be printed' Similar. Note, however, that this particular case did not and does not work in interactive mode with job control enabled. Modified: head/bin/sh/error.c head/bin/sh/error.h head/bin/sh/eval.c head/bin/sh/parser.c head/bin/sh/redir.c head/bin/sh/var.c Modified: head/bin/sh/error.c ============================================================================== --- head/bin/sh/error.c Sun Nov 22 17:25:11 2009 (r199659) +++ head/bin/sh/error.c Sun Nov 22 18:23:30 2009 (r199660) @@ -73,11 +73,15 @@ static void exverror(int, const char *, * Called to raise an exception. Since C doesn't include exceptions, we * just do a longjmp to the exception handler. The type of exception is * stored in the global variable "exception". + * + * Interrupts are disabled; they should be reenabled when the exception is + * caught. */ void exraise(int e) { + INTOFF; if (handler == NULL) abort(); exception = e; @@ -138,8 +142,15 @@ onint(void) static void exverror(int cond, const char *msg, va_list ap) { - CLEAR_PENDING_INT; - INTOFF; + /* + * An interrupt trumps an error. Certain places catch error + * exceptions or transform them to a plain nonzero exit code + * in child processes, and if an error exception can be handled, + * an interrupt can be handled as well. + * + * exraise() will disable interrupts for the exception handler. + */ + FORCEINTON; #ifdef DEBUG if (msg) Modified: head/bin/sh/error.h ============================================================================== --- head/bin/sh/error.h Sun Nov 22 17:25:11 2009 (r199659) +++ head/bin/sh/error.h Sun Nov 22 18:23:30 2009 (r199660) @@ -72,6 +72,8 @@ extern volatile sig_atomic_t intpending; #define INTOFF suppressint++ #define INTON { if (--suppressint == 0 && intpending) onint(); } +#define is_int_on() suppressint +#define SETINTON(s) suppressint = (s) #define FORCEINTON {suppressint = 0; if (intpending) onint();} #define CLEAR_PENDING_INT intpending = 0 #define int_pending() intpending Modified: head/bin/sh/eval.c ============================================================================== --- head/bin/sh/eval.c Sun Nov 22 17:25:11 2009 (r199659) +++ head/bin/sh/eval.c Sun Nov 22 18:23:30 2009 (r199660) @@ -782,7 +782,6 @@ evalcommand(union node *cmd, int flags, savelocalvars = localvars; localvars = NULL; reffunc(cmdentry.u.func); - INTON; savehandler = handler; if (setjmp(jmploc.loc)) { if (exception == EXSHELLPROC) @@ -798,6 +797,7 @@ evalcommand(union node *cmd, int flags, longjmp(handler->loc, 1); } handler = &jmploc; + INTON; for (sp = varlist.list ; sp ; sp = sp->next) mklocal(sp->text); funcnest++; Modified: head/bin/sh/parser.c ============================================================================== --- head/bin/sh/parser.c Sun Nov 22 17:25:11 2009 (r199659) +++ head/bin/sh/parser.c Sun Nov 22 18:23:30 2009 (r199660) @@ -1312,6 +1312,7 @@ parsebackq: { int saveprompt; const int bq_startlinno = plinno; + str = NULL; if (setjmp(jmploc.loc)) { if (str) ckfree(str); @@ -1323,7 +1324,6 @@ parsebackq: { longjmp(handler->loc, 1); } INTOFF; - str = NULL; savelen = out - stackblock(); if (savelen > 0) { str = ckmalloc(savelen); Modified: head/bin/sh/redir.c ============================================================================== --- head/bin/sh/redir.c Sun Nov 22 17:25:11 2009 (r199659) +++ head/bin/sh/redir.c Sun Nov 22 18:23:30 2009 (r199660) @@ -166,8 +166,11 @@ openredirect(union node *redir, char mem /* * We suppress interrupts so that we won't leave open file - * descriptors around. This may not be such a good idea because - * an open of a device or a fifo can block indefinitely. + * descriptors around. Because the signal handler remains + * installed and we do not use system call restart, interrupts + * will still abort blocking opens such as fifos (they will fail + * with EINTR). There is, however, a race condition if an interrupt + * arrives after INTOFF and before open blocks. */ INTOFF; memory[fd] = 0; Modified: head/bin/sh/var.c ============================================================================== --- head/bin/sh/var.c Sun Nov 22 17:25:11 2009 (r199659) +++ head/bin/sh/var.c Sun Nov 22 18:23:30 2009 (r199660) @@ -195,7 +195,9 @@ setvarsafe(char *name, char *val, int fl struct jmploc jmploc; struct jmploc *const savehandler = handler; int err = 0; + int inton; + inton = is_int_on(); if (setjmp(jmploc.loc)) err = 1; else { @@ -203,6 +205,7 @@ setvarsafe(char *name, char *val, int fl setvar(name, val, flags); } handler = savehandler; + SETINTON(inton); return err; }